OK, that's all from me: Thanks for your time and your emails on what was an exciting day's racing that was fairly gruelling to cover from the comparative comfort of an office chair and must have been completely hellish to ride. Tomorrow the peloton, minus defending champion Chris Froome, will travel 194 kilometres from Arras to Reims. I hope you can join me for what will hopefully be a more sedate day's bike-riding.

4.38pm BST

Top 10 on General Classification after Stage Five

1. Vincenzo Nibali (Astana) 20hr 26min 46sec

2. Jakob Fuglsang (Astana) +2sec

3. Peter Sagan (Cannondale) +44sec

4. Michal Kwiatkowski (OPQS) +50sec

5. Fabian Cancellara (Trek) +1min 17sec

6. Juergen van den Broeck (Lotto) +1min 45sec

7. Tony Gallopin (Lotto)

8. Richie Porte (Team Sky) +1min 54sec

9. Andrew Talansky (Garmin) +2min 05sec

10. Alejandro Valverde (Movistar) +2min 11sec

Italy's Vincenzo Nibali has already put himself in pole position to win his first Tour de France. Photograph: Peter Dejong/AP

Updated at 4.40pm BST

4.28pm BST

Stage Five Top 10

1. Lars Boom (Netherlands/Belkin) 3hr 18min 35sec

2. Jakob Fuglsang (Denmark/Astana) +19sec

3. Vincenzo Nibali (Italy/Astana)

4. Peter Sagan (Slovakia/Cannondale) +1min 01sec

5. Fabian Cancellara (Switzerland/Trek)

6. Jens Keukeleire (Belgium/Orica)

7. Michal Kwiatkowski (Poland/OPQS) +1min 07sec

8. Lieuwe Westra (Netherlands/Astana) +1min 09sec

9. Matteo Trentin (Italy/ OPQS) +1min 21sec

10. Cyril Lemoine (France/Cofidis) +1min 45sec

Dutch rider Lars Boom crosses the finish line to win an epic fifth stage of the Tour de France. Photograph: Peter Dejong/AP

Vincenzo Nibali crosses the line 19 seconds behind Boom with his Astana team-mate Jakub Fugslang. The Italian will go well clear - two minutes or more - of the rest of the GC contenders.

Updated at 4.18pm BST

4.14pm BST

Lars Boom is home and hosed: Lars Boom passes under the flamme rouge signifying one kilometre to go. This is going to go down as one of the great Tour de Franc e stage wins - the Dutchman and former cyclo-cross champion has ridden brilliantly this afternoon and, caked in dirt, he punches the air as he crosses the finish line.

4.12pm BST

Nice day for it II Photograph: Christophe Ena/AP

4.10pm BST

Lars Boom makes his move: The Belkin rider looks set fair to win his first ever stage of the Tour de France, having given Vincenzo Nibali and Jakub Fugslang the slip on the final sector of cobbles. He has less than four kilometres to go and is five seconds clear.

4.08pm BST

Ugh! Photograph: Michel Spingler/AP

4.07pm BST

Six kilometres go: Lieuwe Westra gives up the ghost, leaving maillot jaune Vincenzo Nibali, his team-mate Jakob Fugslang and Belkin rider Lars Boom to take on the final set of cobbles. Richie Porte and Fabian Cancellara are 14 seconds behind them. The gap to Andrew Talansky's group is 2min 02sec, while Alberto Contador is a further 18 seconds back.

4.02pm BST

11 kilometres to go: This is an astonishing performance by Astana, who have three riders at the head of the race after successfully tackling the penultimate sector of cobbles. Race leader Vincenzo Nibali and his team-mates Lieuwe Westra and Jakob Fugslang are dictating the tempo, with Lars Boom hitching a ride on their wagon. Behind them, Alberto Contador is in a group over two minutes behind.

3.50pm BST

Two sectors of cobbles left: The lead group emerge from the third from last set of cobbles intact, with Sagan having failed to give Nibali the slip. The penultimate section of cobbles is two-and-a-half-miles long, which is where Fabian Cancellara could make his move.

3.48pm BST

20km: Peter Sagan leads the field on to the third last set of cobbles. If he can put two seconds between himself and Vincenzo Nibali at the finish line, he'll be in yellow tonight. The Contador group is 1min 43sec behind Nibali. The Talansky group is 1min 20sec behind Nibali.

A tamer set of cobbles for the riders. Photograph: Yoan Valat/EPA

Updated at 3.53pm BST

3.46pm BST

21 kilometres: Lars Boom goes for glory and briefly splits the yellow jersey group in two, but Vincenzo Nibali refuses to let him go and welds it back together.

3.44pm BST

23 kilometres to go: Vincenzo Nibali has been a revelation on these cobbles and looks to be having a great time as he negotiates the latest set. Peter Sagan is riding well too and seems to have decided he quite fancies the stage win.

3.42pm BST

Contador update: Alberto Contador and Tejay van Garderen are in a group that's 1min 17sec behind the Nibali group. Andrew Talansky is between the two groups.

3.40pm BST

Chris Froome decides to throw in the towel after his third crash in 24 hours. Photograph: Laurent Cipriani/AP

The peloton exits the cobbles: They've four sets left to negotiate. The breakaway has been reduced to six riders: Samuel Dumoulin (AG2R), Lieuwe Westra (Astana), Tony Martin (OPQS), Tony Gallopin (Lotto), Simon Clarke and Matt Hayman (Orica). Behind them, Belkin riders and cobbles specialists Lars Boom and Sep Vanmarcke have jumped off the front of the yellow jersey group and set off in pursuit of the breakaway.

Spectatprs wait for the pack to pass. Photograph: Christophe Ena/AP

Updated at 3.41pm BST

3.23pm BST

The peloton hits the cobbles:Garmin Sharp rider Andrew Talansky goes down, riding into a spectator as the peloton takes a tight left moments after hitting the pavè. He was forced to swerve to avoid Lotto Belisol rider and GC contender Jurgen van den Broeck, who went over his handlebars into a ditch.

Updated at 3.23pm BST

3.20pm BST

Five cobbles sections and 45 kilometres to go: Chris Froome is out of the race and Alberto Contador is in trouble. He's 30 seconds behind the group in which Vincenzo Nibali and Peter Sagan are riding. Nibali and Sagan's group is 43 seconds behind the breakawa, which has just hit the next sector of cobbles with Tony Martin on the front.

Updated at 3.20pm BST

3.12pm BST

48 kilometres to go: The riders are negotiating the second section of cobbles and it looks quite brutal. The road is narrow, soaking wet, covered in mud, greasy as a box of fried chicken and cobbled to within an inch of it's life. The riders go through almost in single file, doing their utmost to stay up. This is more cyclo-cross than ordinary bike-racing, but hats off to Vincenzo Nibali and Alberto Contador, who are both showing excellent handling skills at the front of the bunch. Nibali even looks quite clean in his smart yellow jersey.

Updated at 3.13pm BST

3.08pm BST

An email from Fiona: "There is more than one team in the TDF or do you work for Rupert Murdoch?" she moans. Quite apart from the fact that Fiona doesn't appear to consider the news that the defending champion has abandoned the biggest cycle race in the world to be important, I love the fact that she thinks I might be working for the Guardian-loathing media mogul Rupert Murdoch.

Updated at 3.09pm BST

3.04pm BST

As in 2004 with Iban Mayo, it's not actual cobbles that did the damage but the run-in. It's as much about getting to them as riding on them

54 kilometres to go: The peloton negotiate the intermediate sprint, but it's barely contested. The peloton is regrouping having been fractured on the first set of cobbles. The gap between them and the breakaway is 1min 30sec.

2.59pm BST

At the exit of theCarrefour de l'Arbre: Stopping the watch at the end of the first set of cobbles negotiated by the riders, it transpires the breakaway group has two minutes 2min 14sec on the peloton, which has split in two. Tejay van Garderen and Alejandre Valverde were in a group 40 seconds behind the main GC contenders, but are about to chase them down.

Everybody seems to have got over the first section of pavèe in one piece, but the big news of the day is that defending champion Chris Froome has abandoned, having crashed twice this afternoon in the wake of yesterday's spill. He's currently travelling to Porte du Hainaut in the back of Sky's second team car. Still, on the plus side, at least they have genuine race contender Bradley Wiggins Geraint Thomas to fall back on.

2.52pm BST

Cobble alert: The peloton negotiates the first set of cobbles and all the remaining GC contenders appear to get over it in one piece as they approach the day's intermediate sprint. Contador, Nibali and Sagan are all towards the head of the field, while behind them in the Sky team car, Chris Froome is assessing the damage to his battered body after three nasty falls in the space of 24 hours.

2.48pm BST

CHRIS FROOME ABANDONS! Before he even gets to the first set of cobbles, the defending champion is forced to withdraw from the Tour. He's taken some beating over the past 24 hours and his latest crash was clearly one too far. He thought long and hard before officially withdrawing, weighing up his options, but his goose is well and truly cooked.

Chris Froome gets into his team car. Photograph: Laurent Cipriani/AP

Updated at 3.08pm BST

2.45pm BST

Chris Froome falls again: The defending champion is suffering all manner of hell today. The defending champion hits the deck hard.It looks like his Tour is over.

2.43pm BST

They're dropping like flies: As the teams jockey for position on the approach to the first set of cobbles, Chris Froome is very, very lucky to avoid another fall. Going around a roundabout, Fabian Cancellara and Tejay van Garderen are notable names among several riders to crash. They remount and set off in chase of the peloton.

2.41pm BST

Trevor Chambers writes

"In response to Robin White (2.01pm)," he says. "Why shouldn’t a pavè expert get say a 10 minute lead on the pavè, in the way a climber might look to get 10 minutes on the peleton in the mountains?" he asks, not unreasonably. "It is the Tour de France (Yorkshire not withstanding) and cobbles are as valid a bit of France as the high Cols. GC is just that – general classification – the winner should be an all-rounder, so to say it penalises the GC contenders makes it sound as though it isn’t a valid stage. Am sure the race handbook/rules does not say that everyone has to let Froome and Contador slug it out in Alps/Pyrenees, so if Cancellara can grab a few minutes now it makes for a better race."

Interestingly, Fabian Cancellara said in his pre-stage interview that today is all about self-preservation for him. I'll believe that when I see it. For anyone who's interested, the bookies have Cancellara (9-2) as favourite to win today's stage. Others in the betting: Peter Sagan (6-1), John Degenkolb (10-1), Sep Vanmarcke (13-1), Niki Terpstra (19-1). If I was having a punt, which I'm not, I'd chance £5 each-way on Terpstra.

Today's breakaway. Photograph: Eric Feferberg/AFP/Getty Images

2.17pm BST

The Tour returns to France

Having set off from Belgium, our breakaway group of seven riders is Gallopin (LTB), Clarke (OGE), Dumoulin (ALM), Martin (OPQ), Westra (AST), Hayman (OGE) and Taaramae (COF). They're 2min 56sec clear of the bunch with 91 kilomtres to go, as they travel through Roubaix.

BMC rider Marcus Burghardt has dropped out of the breakaway and re-joined the bunch after being instructed to do so by his boss, Directeur Sportif DS Yvon Ledanois, in order to help keep his team leader Tejay Van Garderen out of trouble.

"Our priority is to remain united”, said Ledanois. “Our plan today is to back our leader Tejay and we also have a chance with Greg van Avermaet who is our protected rider for the whole first week.”

Updated at 2.18pm BST

2.02pm BST

Look at this!

My colleague John Ashdown has just alerted me to this photograph from near the end of his afternoon's stage.

Robin White has a question

"At what point do the organisers worry about how many people might drop out of the race with injuries today?" he asks. "There are people who have no experience or specialism for this kind of racing being forced to take risks and race seriously on cobblestones in torrential rain.

"On the one hand it will cause carnage in the general classification and a specialist like Cancellara could draw out massive time gains on the established GC contenders. But at the same time, you could see Froome and Contador wiped out with injuries meaning that the two main protagonists won't even make it to the mountains.

"There is a reason why Paris-Roubaix is a one day classic and why it's dominated by Belgians and few of the main riders want to take part in it. I feel for Chris Froome. Falling yesterday and today before the cobblestones start... his head will be full of fear at what lays ahead. Surely going to be a horrendous day for him."

Having taken the skin off his left hip and hurt his left wrist (note the support) yesterday, Chris Froome has already done a number on his right hip and wrist this afternoon. Photograph: Christian Hartmann/Reuters

1.55pm BST

This is like an episode of Casualty

The eight-strong breakaway has been reduced to six, with Martin and Dumoulin chasing to re-join their fellow escapees having remounted following their fall. They are 25 seconds behind the leaders. The gap between the leaders and the bunch, with which Chris Froome has been reunited, is 1min 38sec.

Nice day for it. Photograph: Jean-Paul Pelissier/Reuters

1.48pm BST

Another education from the GCN

Imagine how stupid you'd feel if you didn't know how cycling teams set up their riders' bikes ahead of a race over cobbles. Well, worry no more, because the good people from the GCN are on hand to help you avoid embarrassment.

Updated at 1.48pm BST

1.45pm BST

A crash in the breakaway

Tony Martin and Janier Acevedo go down. I haven't seen footage of it yet, so I'm not sure how bad their accident was.

1.41pm BST

Chris Froome has fallen

With 119 kilometres to go and the riders cycling in torrential rain with gallons of surface water on the road, Chris Froome hits the deck while wearing braces on both the wrists he injured in yesterday's crash. He's put back on his bike and sets off after the peloton, surrounded by his team-mates. Bear in mind, we're nowhere near the cobbles yet - they come at the end of the stage. The first cobbles section comes around the 80-kilomtre mark. The gap between the breakaway group and the peloton is 1min 28sec.

Meanwhile in today's action

The riders set off about 20 minutes ago, have travelled about 20 kilometres and a group of nine have opened a gap of over a minute on the peloton. They are: Lieuwe Westra (Astana), Tony Martin (OPQS), Sam Dumoulin (AG2R), Janier Acevedo (Garmin), Tony Gallopin (Lotto), Marcus Burghardt (BMC), Rein Taarämae (Cofidis), Simon Clarke and Matt Hayman (Orica).

1.18pm BST

Stage Four highlights

Here, for your perusal, are selected highlights from yesterday's stage, the third of this year's Tour de France to have been won by Marcel Kittel in a sprint finish.

Updated at 1.18pm BST

1.09pm BST

Best Wishes + Get Well Soon Dept

Mark Cavendish (shoulder) and Andy Schleck (knee) are both undergoing surgery for injuries sustained in the early stages of the Tour. The very best of luck to both of them - hopefully they'll both recover soon. Indeed, hats off to Mr Cavendish, who seems to have taken time out of his hectic Being In Pain and Understandably Fed up schedule, to phone some random child who'd sent him a "get well soon" card, having seen him crash last weekend.

Gobsmacked is all I can say, a certain @MarkCavendish has just made my daughters day, and of course mine! What a star man! Get better soon

Mark Cavendish is (or was) due to undergo surgery on his injured shoulder today. Photograph: John Giles/PA

12.57pm BST

An email from Andrew Mullinder

"Last night I watched the 2014 Paris-Roubaix on YouTube in order to familiarise myself with pavé racing and tactics, and I have to admit that, rather like the realisation I had later in the evening that Manuel Neuer can identify defensive danger and pass a football better than the English centre-backs, I’m torn about how I feel about it," he says.

"The sections of pavé are, like cols, rated by difficulty, and the five star ones are terrifying: they’re not the type of cobbles we’re used to, but 16kg, Napoleonic era rocks, that are hardly ever driven over and so have not smoothed, and have huge grooves either side. It makes travelling over them a bloody, bone- and bike-wrecking lottery: in one two-kilometre stretch, there were 18 punctures that needed repairing, even before counting other falls and withdrawals.

"It can’t be good that the Tour might be shorn of some of its leading lights through bad luck alone. But then, the Grand National and links golf have elements to luck, too, and the pave makes for thrilling sport. The twenty-odd sections on the Paris-Roubaix act rather like the climbs in the Sheffield stage, wearing down the riders until only the strongest are left, and the thrills, spills, falls, recoveries, and toe-curling tension make a compulsive spectacle."

Paris-Roubaix 2014

12.39pm BST

Today's stage begins at 1pm BST. While you wait, why not watch the latest video diary from Orica Greenedge, which despite the presence of 21-year-old Briton Simon Yates, remains one of the most downright Australian video productions you'll ever see. Maiiiiiiiite.

12.32pm BST

The last wet Paris-Roubaix was in 2002. There were 190 starters and 41 finishers

How to ride cobbles

Here's a splendid guide to riding cobbles, which seems far more complicated than you'd imagine. The likes of Fabian Cancellara and other specialists will be watering at the mouth at the prospect of a stage win today, while most of the main GC contenders will simply be hoping to get through the stage unscathed and without losing any time on their rivals.

The Global Cycling Network's guide to riding cobbles

12.27pm BST

Good day everybody. Have we got a stage for you today, eh? Eh? Well, of course we have, because it would be a bit of a debacle of a Tour de France Stage Five live blog if we didn't. This is the one many of the riders will have been dreading, what with it's nine different teeth-jarring cobbled sectors that could wreak all sorts of havoc and decimate the peloton, particularly if the crazy paving in question is wet. According to Sean Ingle, our man in France, is that it's been pouring down.

Spectators wait on a cobblestone-paved section of a road in Ennevelin, northern France ahead of today's stage. Photograph: Michel Spingler/AP

12.27pm BST

Big news in from Ypres

Due to the appalling weather conditions making the road surface to treacherous, Tour de France organisers have removed two of the nine sections of pavee from today's route as they were believed to be too dangerous and rider safety is of paramount importance. Never fear, masochists and schadenfreude merchants - we still have 12 kilometres worth of the slippery, bumpy stuff to look forward to.

The sectors which have been removed are Sector Seven , the 1,000-metres stretch of cobbles at Mons-en-Pévèle, and Sector Five, which a 1,400-metres long portion from Orchies to Beuvry-la-Forêt. It reduces the number of pavés sections to 13 kilometres.

Updated at 12.30pm BST

12.20pm BST

Will Fotheringham on Stage Five

The Tour can easily be lost here, with nine of the celebrated cobbled sections that figure in Paris-Roubaix, the most coveted one-day race in cycling. The Tour hasn’t included this much of the cobbles since the 1980s; last time they featured in 2010, Lance Armstrong and Fränk Schleck were among the victims. The dangers are multiple: the pave sections are narrow and the poor surface makes falling or puncturing highly likely, and the continual crashes and punctures mean that team cars may not be in attendance because they tend to get held up.

That means it’s vital to have not just the leader, but several riders alongside him at the front. That in turn makes for a hectic battle to get the best position at the head of the peloton before the sections begin; it’s like the run-in to a bunch sprint, so on some occasions – as with Iban Mayo in 2004 – a favourite’s Tour can end due to a crash before the cobbles have even begun.

The first section, 68.5km from the finish, is Carrefour de l’Arbre, the key zone in the finale of Paris-Roubaix, so the jostling will start at least 15km before they get there. The only Tour winner of recent years to take on Roubaix is Bradley Wiggins, but in practice anything can happen and probably will.